Printing device.



No; 718,189; PATENTED AN. "13, 1903.1

M., J. BULGER.- PRINTING DEVICE.-

.APPLIOATION FILED DEG. 18,1901.

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a l x Wilmeooao UNITED STATES PATENT OFFICE.

MATTHEW J. BULGER, OF NEW YORK, N. Y.

PRINTING DEVICE.

SPECIFICATION forming part of Letters Patent N o. '7 18,189, dated January 13, 1903.

Application filed December 18, 1901. Serial No. 86,340. (No model.) 7

To all? whom it may concern:

Be it known that I, MATTHEW J. BULGER,

a citizen of the United States,residing at New York, State of New York, haveinvented certain new and useful Improvements in Printing Devices, of which the following is a clear, full, and exact description.

My invention relates to improvements in printing devices; and my object isto provide an overlay for use in a printing-press which will give better results than the overlays heretofore known to the art.

My invention will bedefined in the claims.

In the drawings showing the preferred embodiments of my invention, Figure 1 shows the face of an embodiment of my electrotype overlay. Fig. 2 shows a cross-section (relief greatly exaggerated) of Fig. 1' on line a; 60, Fig. 3, aview of an alternative construction of overlay; Fig. 4, a section on line'y 'y of Fig. 3, and Fig. 5 illustrates my overlay in position on a simple printing-press. Fig. 6 is a cross-section through roll 0 and overlay.

It is well known in the printing-press art that'when a picture is printed from a reliefplate an electrotype, for example the proper gradations of tone in the print are not obtained if the sheet on which the picture is printed is pressed upon the relief-plate with a uniform pressure over its Whole surface.

In such a case the deep tones in the picture are weak and the intended differences in tone are not produced. In order to remedy this defect to a certain extent, it has been customary to provide overlays by which additional pressure will be produced upon'the sheet at the points where the deepest tones occur in order to cause the sheet to take up more ink from the plate at those portions, and thereby partially obtain the desired gradations of tone. The usual method of forming these overlays has been to pull a proof from the press and then by hand out out small pieces of paper corresponding to the intended deeper tones and paste them on the face of the print overthe portions whose tones are to be deepened,making the intended black portions thickest and the intermediate tones relatively thinner. This overlay is then fastened to the tympan and produces additional pressure on the printed sheet at the portions so reinforced. It will be obvious, however,

that this method of producing an overlay has many serious objections. The pieces of paper must be cut out by hand and pasted on the proof by hand merely according to the judgment of the workman, and the overlay so produced is invariably unsatisfactory in many respects. The pieces of paper may not have been correctly registered with the portions of the proof intended to be intensified, which would result in an undesired change in tone in parts of the next proof, and the overlay must then be altered, and in any case it is impossible from a practical point of view to produce an overlay in this manner which will give the desired effect to the details of even asimple picture. The labor and time required is great, and, furthermore, whenever several duplicate original relief-plates are to be printed from at the same time, as is often the case, a separate overlay must be made for each plate, and these different overlays may not be exactly alike, in which case the proofs from the different plates will differ from each other in tone. Such an overlay and the abovedescribed usual method of producing the same are therefore unsatisfactory and unscientific in many respects no matter how skilful the workman may be. The overlay of my invention avoids the above objections and yet has the desired gradations in relief, even to small details, and I prefer to produce it by forming an electrotype-shell which is a duplicate of the plate to be printed from and then cutting down the back of the same till the shell is so thinthat'it is pliable and is smooth on the back. This may be applied to the tympan so as to register with the plate to be printed from and will have a proper relief at every point Where added pressure is needed, even to the smallest details.

Referring to the drawings, Fig. 1 shows a plate to be printed from and also my preferred form of overlay, as they are-duplicates so far as the relief on the face is concerned. Any number of these may be formed at the same time by the well-known process of producing electrotype-shells from the original plate, thus avoiding the necessity of separately building up an individual overlay for each plate to be printed from when several plates are used in the press at the same time. Furthermore, each of these shells is an exact ICO duplicate of every other and also of each of the electrotype-plates to be printed from.

An electrotype-shell is rough on the back when it comes from the electrotype-vat, and I cut the back down until the shellis thin and pliable and then smooth the back. I have found that a thickness of three onethousandths part of an inch for the finished overlay answers admirably; but I do not limit myself to this thickness. Fig. 2 shows a cross-section (relief greatly exaggerated) of the finished overlay as if taken at line a: a; of Fig. 1. The portions e 6 represent the thickest portions of the overlay registering with the portions of the relief-plate B which are intended to give the deepest tones. The portions ff are of a slightly less thickness to give aless pressure on the portions intended to have intermediate tones, and the portions g are of still less thickness to give no pressure whatever on the portions of the print which are intended to be white. I then apply the overlay a face downward to the tympan on roll 0, as simply illustrated in Fig. 5, so that it registers with the reliefplate I), and I preferably cover it with two or three thicknesses (Z (Z of paper, as shown in Fig. 6. The sheet of paper to be printed on is then applied to the tympan and printed in the usual way, and the overlay being pliable will give through it the necessary added pressure to the sheet at the portions desired.

In Figs. 3 and 4 I have shown an overlay which is thin and pliable and smooth on the back, but which has on its face in relief a reverse of the picture on the plate 1). Such an overlay should be applied to the tympan back downward and relief-face upward, so that it will register with the relief-plate b to be printed from. Both the overlays of Fig. 1 and Fig. 3 have in relief a cut or picture corresponding totl1at is, having substantially the same picture as--the plate to be printed from, the only difference being that the out or picture is reversed in Fig. 3. Each of the above overlays has a hard relief; but as the overlay is thin and pliable the relief-plate b will not be injured by its use even if a particle of dirt, for example, should get between the overlay and the relief-plate, for the overlay will then yield and prevent such injury, as the tympan on roll 0 is soft and allows the overlay to thus yield.

I am aware that the above method of producing the overlay and the characteristics of the above overlays may be varied without departing from the scope of my invention as claimed, and I therefore do not desire to be limited to the particular method of making or to the particular embodiment of overlays heretofore described.

What I claim is 1. A printing-overlay consisting of a pliable sheet having on one side thereof in hard relief (so that it will not spread under pressure) and integral with said sheet, a cut corresponding to the plate to be printed from.

2. A printing-overlay consisting of a pliable sheet having on one side thereof in hard relief (so that it will not spread under pressure) and integral with said sheet a duplicate of the plate to be printed from, and on the other side a smooth surface.

3. In a printing-press in combination, a relief-plate, a soft tympan, and an overlay mounted on said soft tympan and registering with said plate, said overlay consisting of a pliable sheet having on one side thereof in hard relief (so that it will not spread under pressure) and integral with said sheet, a cut corresponding to said relief-plate.

4. A printing-overlay consisting of a pliable metallic sheet having on one side thereof in relief and integral with said sheet a cut corresponding to the plate to be printed from.

5. A printingoverlaying consisting of a thin pliable metallic sheet having on one side thereof in relief and integral with said sheet a duplicate of the plate to be printed from and on the other side a smooth surface.

(3. In a printing-press in combination a relief-plate, an overlay registering with said plate and consisting of a thin pliable metallic sheet having on one side thereof in relief and integral with said sheet a duplicate of said relief-plate and on the other side a smooth surface.

7. A printing-overlay consisting of a pliable electrotype.

8. A printing-overlay consisting of a thin pliable electrotype duplicate of the plate to be printed from.

9. In a printing-press in combination a relief-plate, and an overlay registering with said plate and consisting of a thin pliable electrotype duplicate of the said relief-plate.

10. In a printing-press in combination a relief-plate, a tympan, and an overlay thereon registering with said relief-plate and consisting of a thin pliable electrotype duplicate of the plate to be printed from, and one or more sheets of thin pliable material carried by said tympan and covering said overlay.

11. A printing-overlay consisting of a thin pliable electrotype corresponding to the plate to be printed from and smooth on the back.

Signed at New York, N. Y., this 16th day of December, 1901.

MATTHEW J. BULGER.

Witnesses:

CHARLES STUART FoLsoM, FRANCIS I. FROIDEVAUX. 

